Telephone-exchange system



D. IVI. TAGGAHT.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED sEPT.4,1919.

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1M-hl IIH" wir To all wko/m t may concern." t z GGART,

lala 1lAV it E if l n i niiwsoivjiu. meenam, or nas@ Gitarren, ivnw anneau, assieiicii. To WESTERN anne-` l TRICiCOMPANY, INCORPORATED, OF NEW vom;

isaaacs. y y f i Application alaseptember` Be it known that LVDAwsoN M. a citizenoii the United States,` residing at East Grange, in the county `of Essex` and State of New` Jersey, have invented certain new and useful Improvements in Telephone- Exchange Systems, of which the following` is a full, clear, concise,iand exact description.- l v i Y This invention relates to telephone eX change systems; .but more particularly to such systems inwhich common battery and Y local battery telephone lines terminating at a central oiice may be interconnected indiscriminately.

' The objectof the` present inventionis the provision of improve-d signaling means for telephone systems of this character. u

In accordance with thefjobject of this inc ventionA a `universal link circuit is i provided with a signaling device. operative inone man-V ner to give a disconnect signal from aline or either-character and operative in a differentV manner to give a recall signal. from a line of either character. i

The inventionrwill loemoreclearly understood when considered in connection with the following description taken'finv conjunc tion with the accompanying drawingwhich formsua partthereof.` Y y There are shown in the drawing a common battery telephone line A and aflocal battery or magneto telephone line B terminating at a central office atwhich is located a universalcord circuit C` forinterconnectingtelephone lines of the types represented bythe lines A and B. l i p The subscriber at the station on telephone line -A desiring to converse with the subscriber at the station on telephone line removes the receiver from the switch-hook causing the energization of` line relay `4 and i the lighting of the line signal 5. The `op-` erator, observing the lighted condition `o f this lamp7 inserts plug 6 `of the cord circuit C into jack 7 of the telephone'line A, therebycausing the operation of cut-off relay .2 3, relay`9 and Inarginalkrelay A10 over a circuit extending `from battery', through the lett-i` hand winding ofrelay 9, winding'of `marginal relay 10, sleeve contacts ottheplug 6 andthe jack p to ground. RelayV 9 in closing vits "contactconnects a source of battery supply with the winding; of relay; 14 through normally Specification of I closed contact 7, winding of" cut-01T` relay 8,*

YORK, N. Y., A CORPORATIGN 0F NEW TELEPHONE-,EXCHANGE svsrniin Patented Uteto 4, 191e seriaiiio; 321,704. n

Letters Patent.

of the listening key 15. The operation of'relay 10 disconnects the wind-i ings of relay the talking conductors of the cord circuit C and -connects battery to the ring side of the linethrough the right-hand winding of relay 13 `and grounds the tip side oi' the line so that the operation of relay 13 is controlled through the contacts of the switchhook at thestation on telephone line A. Supervisory lamp41-2 and relay 11 are momentaril .operated upon the closure of the left-hand contact' of 'relay 10, since this contact is closed before the opening of the normal con tact of relay 13. Relay 13 in operating causes "the energization circuit extending from battery, through the normal contact of listening key 15, contact of relay 9, winding of relay`14, right-hand normal contact of relay 11, alternate contact;

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13 from bridged relation with of relay 14 over a of relay 18and the supervisory lamp 12 and the right-hand winding of relay 11 in parallel to ground. `Relay 11 is marginal and does i not operate when included in circuit with the winding of relay 14 and when its winding is shunted by the supervisory lamp Belay 14 in operating completes alock` ing circuit for itself through its left-liand fao Contact andthe left-hand Contact of relay 11.

The operator may now `actuate listening key 1 5 to connect t-hetelephone set in circuit with the telephone line.` The actuation-of `the listening lkey also opens the circuit of and causes the release of erator after being advised that connection is desired with telephone line B inserts plug '16 of the cordcircuit C into jack 17 of the telephone line B, thereby causing the operation of cut-oiirrelay 18 over a circuit extend- `ing from battery, through the right-handwindiliig of relay 9, winding of` marginal relay19, sleeve contacts of the plug 16 and thejack 17, winding of cutoff relay 18 to ground; Cutfoiii relay 1Sin operatingdisconnects line relay 2O from the linethereby preventing the operation thereof when the` party"` at the station ori-telephone line B actuatesthemagneto 21 to give a disconnect or la recallfsignal." `Relay 19 is marginal and does not operate Vwhen included in circuit with the high resistance winding 01:' cut-off relay V18.1

relay 14. The opf the ringing key (not shown) for connecting a source of ringing current With the line `for causing the operation of the call bell of l subscriber at B upon responding to the operation of the call bell by removing the receiver from the switchhook, is enabled to converse With the party at A without any further operation on the part of the operator. .1

The conversation having been completed, the parties at A and B restore thereceivers to the switchhoolzs, the party at B giving a slight turn on the handle of the magneto 21 so that the apparatus at thecentral office will function to give a disconnect signal to the operator. Y

The restoration ofthe receiver to the switchhook by the party at A causes the deenergization of relay 13 which closes atV its normal contact the operating circuit of supervisory lamp 12 and relay 11 which may be traced from battery through the left- `hand alternate contact of relay 10, normal contact Vof relay 13, and the supervisory lamp 12 and the right-hand winding of relay 11 in parallelto ground. Relay 11 in operating locks up over a circuit extending from battery through the normal contact of listening key 15, contact of relay 9, winding and left-hand alternate contact of relay 14, and the left-hand winding of relay 11 to ground. rlhe supervisory lamp 12 lights upon the closure of its operatingcircuit to` furnish a disconnect signal to the operator denoting that the conversation has been completed. n

The party at B in actuating theA magneto 21 causes the energization of relay 22 as long as` current from the magneto 21 is traversing the line. rlhe closing of the alternate contact of relay 22 causes the energization of relay 23 over a circuit extending from battery through the normal contact of listening key 15, contact of relay 9, Winding of relay 23, left-hand normal contact of relay 24, alternate contact of relay 22 and the supervisory lamp 25 and the left-hand Winding of relay 24 in parallel to ground. Relay 23 in operating establishes a locking circuit for itself which may be traced from battery through the normal contact of listening key 15, contact of relay 9, winding and right-hand contact of relay 23 and the right-hand contact of relay 24 to ground. Relay 22, upon being de'e'nergiZ-ed, causes the lighting of supervisory-lamp'25 and the energization of relay 24 over a circuit extending from battery through the left-hand contact of relay 23, right-hand normal contact of relay 26, right-hand normal contact of relay 19, normal contact of relay 22, and the supervisory lamp 25 and the left-hand winding of relay 24'in parallel to ground. The

lighting of the supervisory lamp 25 serves as a disconnect signal which is an indication to the operator that the conversation has been completed and that the plug 16 may he disconnected from the jack 17. Relay 24 in operating locks up in series with relay 23.

The operator, upon observing the lighted condition of the supervisory lamps, may remove the plugs from the respective line jacks which restores the system to normal.

Assuming now that the party at A wishes to recall the operator before the plug 6 has been withdrawn from the jack 7. The party at A removes the receiver from the switchhook which causes the operation of relay 13. Relay 13 in operating closes at its alternate contact the energizing circuit of relay 28, which may be traced from battery through interrupter 29, left-hand winding of relay 28, right-hand alternate contact of relay 11, alternate contact of relayV 13, and supervisory lamp 12 and the right-hand winding of relay 11 in parallel to ground. Relay 28 in operating establishes a locking circuit for itself which may be traced from battery through the normal contact of listening key 15, cont-act of relay 9, right-hand contact and winding of relay 28 to ground. The locking up of relay 28 aerforms no useful function at this time.. interrupter is now connected in circuit with the supervisory lamp 12, this lamp is intermittently lighted to give a signal of a different character than when serving as a dis- -connect signal in order that the operator may clearly distinguish between the two signals.

The party at B in desiring to recall the operator before the connection has been taken down turns the handle of the magneto 21 several times which causes the encrgization of relay 22. Relay 22 is held operated sufliciently long to cause the energization of the relay 26 over a circuit extending from battery through the contacts of the interrupter 27, right-hand winding of relay 26, left-hand alternate contact of relay 24, alternate contact of relay 22, and the supervisory lamp 25 and the left-hand winding of relay 24 in parallel to ground. A locking circuit 'for relay 26 is thereupon established over a circuit extending from battery through the contact of the listeninglrey 15, alternate contact of relay 9, left-hand alternate contact and winding of relay 26 to ground. The supervisory lamp 25 is thereupon intermittently lighted over a circuitl extending from battery through the contacts of the interrupter 27, right-hand winding and alternate contact of relay 26, normal contact of relay 19, normal contact of relay 22, and the supervisory lamp 25 to ground. The operators attention is thereby directed to the flashing of this lamp.

That is claimed is:

1. A telephone system comprising com- `manner to furnish g lay operative over lines of either character `of a different character. y n i 2. A telephone exchange system comprising common battery and local battery telephone lines, a link circuit for interconnecting said lines, al signaling device in the link circuit, and means controlled over a line of either character to cause the continuous operation of the signaling device to furnish a disconnect signal and the intermittent operation of the signaling device to furnish an automatically sustained recall signal.

3. A telephone exchange system comprising common battery and local battery telephone lines, a link circuit for interconnecting said lines, a signaling device, means in the link circuit operative over lines of either character to cause the operation of" said signaling device in one manner to furnish .a disconnect signal, and a relay Vcon-` trolled over a line of either character and coperating with said means to cause said signaling device to operate in a different manner to furnish an automatically sustained recall signal.

LAA telephone exchange system comprising common battery and local battery telephone lines, a link circuit for interconnecting said lines, a signaling device, a re- 7 and means controlled by said relay to cause the continuous operation of said signaling device tofurnish .a disconnect signal from lines of either character and to cause the intermittent operation of vice to furnish an automatically sustained recall signal from lines of either character.

5. A telephone exchange system comprising common battery and local battery telephone lines, a link circuit for interconnecting said lines, a signaling device, a relay `in the link circuit and controlled over .a connected line for causing the continuous operation of said signaling device to furnish a disconnect signal7 an interrupter,V and a second relay controlled through the contacts of said first relay -for connecting said interrupter in circuit With said signaling device for causing the intermittent operation thereof to iurnish a recall signal from lines of either character. y

6. A telephone exchange system comprising common battery and local battery telephone lines, a link circuit for interconnecting said lines, a signaling device, means for operating the signaling device in one a disconnect signal `:from lines of either character, and means for operating the signaling device in a different type of connected line to said signaling del manner to furnish ,an automatically sustainedrecallsignal from lines of either character.

7. Atelephone `exchange system comprising common battery and local battery telephone lines, a universal cord circuit for indiscriminately interconnecting said lines, .a relay in the cord circuit and controlled overa connected line, a second relay in said cord circuit controlled over a cord circuit conductor, and a signaling device controlled jointly by the contacts of said iirst mentioned and said second relay and operative upon the energization or denergization of said second relay depending upon the type of connected line to furnish a continuous disconnect signal from a line of either charac- `ter and operative in a different manner to furnish an intermittent automatically sus-` tained recall signal from lines of either character.

8. A telephone exchange system comprising common battery `and local battery telephone lines, a link circuit for interconnecting said lines, a signaling device, and

line controlled means for causing the operation of said signaling device to furnish like disconnect signals of one character for both types of lines Vand like automatically sustained` recall signals of another character for b oth types of lines.

9. A telephone exchange system coinprising' a plurality of local battery telephone lines, a link circuit for interconnecting said lines, a signaling device, and means in th'elink circuit controlled over the line for causing' said signaling device to furnish a signa] oi one character for disconnectrand an automatically sustained signal of another character for recall.

10. A telephone exchange system coniprising common battery and local battery telephone lines, a link circuit for interconnecting said lines, a signaling device controlled over a line of either character and operating independently of the type of connected line to furnish a disconnect signal of one character and a recall signal of another character, and means associated solely With said link circuit and independent of the connected lines for `discontinuing the recall signal.

11. A telephone exchangeV system comprising common battery and local battery telephone lines, a'link circuit for interconnecting` said lines, a signaling device, a relay in the link circuit and controlled over a cony said link `circuit relay and said second relay Voperated recall signal, and means associated solely With said link circuit .and independent ofthe connected lines for discontinuing the recall signal.

. In witness whereof, I hereunto subscribe 10 my name this 29th day of August, A. D. 1919.

DAWSON M. TAGGART. 

